I am puzzled by the problem reported by the first poster in this thread:

http://www.dynare.org/phpBB3/viewtopic.php?f=1&t=2829

I am able to reproduce the problem at 2nd and 3rd order, but not at 1st.

At 2nd order, given the decision rules, is it clear that for a
shock to "eta", if "e" is maintained to zero, then "a" should remain
constant.

However it is not what happens in the IRF graphs: "a" moves, by a not so
small amount.

Is this a bug in the IRF generation code, or am I missing something
obvious?

Best,